MSE Source Buffer Timeline Switching for Preroll and Midroll

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Solution Overview

Problem

Existing MPEG DASH standards struggle with nonlinear playback and pre-roll ad insertion, especially when using W3C Media Source Extensions and Encrypted Media Extensions for protected live content, failing to seamlessly integrate auxiliary content with main media content.

Innovation Solution

The implementation of auxiliary media presentations independent of main media presentations, utilizing MPD chaining to manage pre-roll and mid-roll content through a modified MSE source buffer with timestamp offset adjustments, ensuring seamless playback transitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If MPD chaining and pre-roll ad insertion are used to address nonlinear playback, then auxiliary content integration is improved, but compatibility with W3C Media Source Extensions and Encrypted Media Extensions deteriorates

Engineering Contradiction:

Improveauxiliary content integrationVSAvoidcompatibility with W3C MSE and EME

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the media presentation into separate Period elements in the MPD file - one for main content and one for auxiliary content (pre-roll/mid-roll ads). This segmentation allows independent handling of different content types while maintaining compatibility with W3C MSE and EME through proper timestamp offset management in the SourceBuffer

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism using timestamp offsets as a mediator between the auxiliary content timeline and the main content timeline. This offset acts as a bridge that allows the SourceBuffer to seamlessly switch between main content and auxiliary content without breaking EME protection or MSE compatibility

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If a single linear timeline is used in MPEG DASH, then standard playback is simplified, but nonlinear operation and independent timeline management become difficult

Engineering Contradiction:

Improvestandard playback simplicityVSAvoidnonlinear operation capability

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent makes the media timeline dynamic by allowing the Player to switch between different Period elements based on playback state. The MPD structure enables dynamic insertion of auxiliary content periods at appropriate timestamps, transforming the static linear timeline into a flexible structure that can accommodate nonlinear operations while maintaining simplicity through standardized MPD syntax

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP4226601B1Method and apparatus for supporting preroll and midroll during media streaming and playback

Publication Date: 2026.04.15 TENCENT AMERICA LLC

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AI summary

A method and apparatus may be provided for signaling an auxiliary media stream during a main media stream using a MSE buffer including one or more main media segments being appended to a MSE source buffer based on one or more respective main time stamp offset and one or more auxiliary media segments being appended to the MSE source buffer based on one or more auxiliary period attributes associated with the one or more auxiliary media segments. An auxiliary period attribute may be a period type element comprising a start time attribute indicating a first time offset at which a main media segment among the one or more main media segments may be stopped during a preroll or midroll insertion to play an auxiliary media segment among the one or more auxiliary media segments. The media segments and auxiliary media segments may be dispatched.